"The Bible says, 'What then shall we say, brothers? When you come together, everyone has a hymn, a word of instruction, or an interpretation' — all of this done for the strength of the church," said Greg Stultz, who leads the house church. "Where is that being done?"

During church, anyone can suggest a song and instead of a sermon, the group discusses anything they’ve been dealing with lately.

At Redemption Church, a group of house churches in Bristol, Pa., Pastor Gary Alloway said he had initially wanted to build a traditional church, but soon realized he needed a new plan.

"I'm not writing a sermon for 12 people,” Alloway told his small congregation. “How about you guys come over to my living room? We'll open a Bible, we'll talk about it, we'll eat together.”

The house church is an idea that is biblical, said L. Michael White, a Christian origins professor in Texas.

"Where do they meet?" White asks. "We do have references in ... the letters of Paul to meeting in someone's home — or, basically, the church in your house."